Is itching really a sign of wound healing?

Most people have heard the common expression that itching indicates that a cut or wound is healing.  Is there any scientific basis to this belief or is this just an "old wives tale"?
   
Phases of wound healing. The body's initial response to a cut or break in the skin is to stop bleeding. This occurs through constriction of blood vessels and the formation of a clot. Following this, 3 major phases lead to healing of the wound.  The first is the inflammatory phase in which the body sends antibodies, white blood cells, growth factors, enzymes and nutrients to the area. These help to "clean up" damaged tissue and start the healing process. In the second phase, known as proliferation, new blood vessels grow into the area of damaged tissue and specialized cells known as fibroblasts lay down collagen to bridge the wound. The final phase, remodeling, can last for many months. During this phase, scar formation occurs and the collagen in the wound undergoes maturation, becoming more like tissue prior to the injury.
 
Do all wounds itch?  Although not always the case, at some point during the healing process, most wounds will itch. This has been noted to be particularly true in the case of burn wounds in which itching can be a highly distressing symptom.

What causes wounds to itch?  Several explanations for wound itching have been proposed, some based on chemicals released during the inflammatory phase of healing and others based on mechanical factors during proliferation.

• Histamine is a chemical best known for its association with itching during allergic reactions.  Histamine is also released by cells in response to injury and is believed to contribute to itching, particularly in the early phases of wound healing.
   
• Neuropeptides, small, protein-like molecules that help nerve cells "talk" to one other, are also believed to cause itching during wound healing. One particular neuropeptide known as "Substance P" transmits pain or itch-related information from nerves in the skin to the brain.
   
• During proliferation, collagen and skin cells bridge the wound, pulling the edges of the skin back together. This mechanical process is thought to activate nerves that is perceived as itching by the brain.

The notion that itching is an indication of healing does appear to have basis in scientific fact.  A more accurate way of looking at this is that most wounds will eventually heal, and itching, whether because of chemical or mechanical reasons, is part of this process. Perhaps the next issue to be addressed in wound healing research should be "to scratch or not to scratch"!  

Choosing the right mattress

Some like their sleeping mattress to be firm, some like it soft, some prefer it to be filled with water and some had just as soon sleep on the floor.  To confuse things further, there are claims that adjustable beds, sleep number beds, or memory foam mattresses are best at achieving that elusive great night's sleep.  Almost everyone has heard that a firm mattress is the best type for those with back problems.  Is there scientific proof for this or is this another medical myth?  Let's look at some of the published reports pertaining to the type of mattress that we chose to sleep on, with special consideration for those with chronic back pain. 
In spite of spending about one-third of our lives lying on mattresses, there has been relatively little scientific study of mattress design.  In describing the ideal sleeping surface, Cornell University's Ergonomics group recommends that a mattress:

1)  Conforms to the spine's natural curves and to keep the spine in alignment when you lay down.

2)  Distributes pressure evenly across the body to help circulation, decrease body movement, and enhance sleep quality.

3)  Minimizes the transfer of movement from one sleeping partner to the other.

4)   Has perimeter edge support.

The Cornell group, however, was unwilling to go out on a limb to suggest one brand or type of mattress over another, since sleeping comfort is to a large degree a personal preference.

Some of the more interesting (and expensive) mattresses on the market, are those made with NASA-developed Visco elastic material that conforms to the body.  The Tempur-Pedic line of mattresses is made with this so-called "memory foam", touted to relieve pressure points and lead to a better night's sleep.  While consumer approval of these mattresses is high, scientific evidence of their superiority in those without special concerns such as diabetes or arthritis is lacking.  There is, however, scientific evidence that "memory foam" mattresses are effective in reducing pressure sores in those confined to bed.

One very interesting study reported in the medical journal, Applied Ergonomics, challenged the notion that firmer is better. In this study, medium firm mattresses specifically modified with foam or latex based on sleeping position was found to reduce discomfort and to increase sleep quality in those with chronic back pain.  Of course not many of us have the opportunity to consult with an ergonomic expert to design a "prescribed" mattress.

Owner experience data reported by the claimed "unbiased and independent"; consumer web site, Sleep Like the Dead,  indicates that most people rate memory foam, air, and latex mattresses highest in owner satisfaction, while innerspring mattresses overall rate the lowest.  They also found from owner's experience that greater the sagging depth of a mattress, the more likely the mattress will cause back discomfort.

Choosing the ideal mattress seems to be a highly individual consideration.  Rather than taking the advice of a review or someone else's word, spend some time trying out mattresses where they are sold.  Don't feel self-conscious about lying down for a few minutes on each one that you are considering.  Some mattress outlets even offer a 30-90 day return warranty if once you get the mattress home you find that it's just not right for you.  One-third of your life is too long a time to spend on an uncomfortable or, worse yet, harmful mattress.

Liver damage tied to over-the-counter dietary supplements

In 2003, the National Institutes of Diabetes and Digestive and Kidney Diseases established the Drug-Induced Liver Injury Network to document cases of drug-induced liver injuries. Between 2004 and 2013, the Network identified 839 patients with liver damage due to prescription medications or to non-prescription dietary supplements.  This registry excluded cases of acetaminophen-related liver damage, which is by far the leading cause of liver toxicity in the U.S.  Acetaminophen is the main ingredient in Tylenol and is also contained in hundreds of prescription and over-the-counter medicines. Of the cases of liver toxicity investigated, 130 (15.5%) of the subjects were judged to have experienced liver injury caused by herbals or dietary supplements.  While this is a fairly small percentage of the total number of subjects, it is doubtful that any of these victims recognized the potential that an over-the-counter supplement had for causing serious liver damage. 


Who is taking these supplements?  It has been estimated that nearly half of U.S. adults are taking an herbal or dietary supplement.  This is particularly true among women, non-Hispanic whites, individuals over the age of 40, and those with higher levels of education.  The National Center for Statistics estimated that sales of herbals and dietary supplements amount to $33.9 billion in 2007. Examples of the some of the most common dietary supplements include multivitamins, minerals, calcium and fish oil.

Which supplements were found to be responsible?  Of the subjects with liver injury, approximately one third were taking a supplement marketed to promote bodybuilding. The non-bodybuilding supplements implicated included weight loss products (e.g. Ripped Fuel Extreme Fat Burner), energy boosters (e.g. Up Your Gas), Chinese herbs, Ayurvedic (Indian) "medicines", and colon cleansers (e.g. Cellular Research Formulas - Dual-Action Cleanse).

How serious was the damage to the liver?  All subjects were found to have abnormal liver function tests and elevated levels of bilirubin, an orange-yellow substance made during the normal breakdown of red blood cells, in the blood stream.  Most experienced jaundice (yellow eyes or skin), abdominal pain, and itching.  While most subjects eventually recovered after stopping the supplements, 13 of the subjects (none of whom were taking bodybuilding supplements), died or underwent liver transplant.
 
Aren't herbals and supplements regulated by the government?  Unlike prescription drugs that must be proven safe and effective for their intended use before they are made available to patients, there are no provisions for the U.S. Food and Drug Administration (FDA) to "approve" dietary supplements for safety or effectiveness.  Also, manufacturers and distributors of dietary supplements are not currently required by law to record, investigate, or forward to the FDA any reports they receive of injuries or illnesses that may be related to the use of their products.

If you're considering taking an herbal product or dietary supplement:

1.  Consult your doctor or pharmacist.  If you are uncertain about the possible harms or want to know if the claims regarding a supplement or herbal are believable, talk it over with a medical professional.  This is particularly important if you are already taking a prescription medication or other dietary supplements. The potential for problems goes up with the number of different medications or supplements someone is taking.
     
2.  Report any side effect or new problem.  Complications or interactions related to a supplement should be identified and addressed as quickly as possible. Ideally, this information should be reported to the FDA via MedWatch.
    
3. Be wary of certain types of supplements.  Those that are promoted to bring about weight loss, sexual enhancement and bodybuilding have been found to be particularly troublesome, not to mention, ineffective.  

Carbon Monoxide Poisoning

Carbon Monoxide is a compound composed of carbon and oxygen and has the chemical formula---CO.  It is a highly poisonous gas that can result in asphyxiation when inhaled.  Carbon monoxide is formed when fossil fuels (gas, oil, kerosene, wood, charcoal, etc.) are burned with insufficient amounts of air.  Automobiles, space heaters, portable generators, ovens, furnaces, fireplaces, water heaters, and gas powered clothes dryers are all common sources of carbon monoxide production.  CO poisoning occurs when these appliances are not working or vented properly and dangerous levels of CO build up.

What causes CO poisoning? Hemoglobin within red blood cells is responsible for transporting oxygen to the body.  With elevated levels of CO in inhaled air, CO binds to hemoglobin instead of oxygen. This results in less life-sustaining oxygen being supplied to body tissues and vital organs such as the brain and heart.
 
Are there symptoms associated with CO poisoning?  Carbon monoxide is an odorless, colorless gas, so it can be very difficult to detect.  At moderate levels, the most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. Higher levels of CO intoxication can result in loss of consciousness and death.  Some people have been fooled into thinking that their symptoms were due to a cold or flu, whereas they were really experiencing CO toxicity.
 
How big a problem is CO poisoning?  Each year, over 400 deaths occur due to CO poisoning and many more seek medical treatment.  The risk of succumbing to CO poisoning is highest among the elderly, those with chronic respiratory or heart problems, children, and people with anemia.

What do I do if I suspect CO poisoning? If you experience symptoms that you think could be from CO poisoning, get to fresh air immediately.  Open doors and windows to ventilate the house and turn off all fuel-burning appliances.  Go to an Emergency Room as quickly as possible and inform the staff that you suspect CO poisoning.  A fairly simple blood test that measures the level of a compound called carboxyhemoglobin can be done to confirm the diagnosis.

 How can I decrease the risk of CO poisoning?  The Centers for Disease Control has offered the following suggestions to help prevent CO poisoning:

• Do have your heating system, water heater and any other gas, oil, or coal burning appliances serviced by a qualified technician every year.
• Do install a battery-operated or battery back-up CO detector in your home and check or replace the battery when you change the time on your clocks each spring and fall. If the detector sounds leave your home immediately and call 911.
• Do seek prompt medical attention if you suspect CO poisoning and are feeling dizzy, light-headed, or nauseous.
• Don't use a generator, charcoal grill, camp stove, or other gasoline or charcoal-burning device inside your home, basement, or garage or near a window.
• Don't run a car or truck inside a garage attached to your house, even if you leave the door open.
• Don't burn anything in a stove or fireplace that isn't vented.
• Don't heat your house with a gas oven.

Can I feel safe with a CO detector in the home?  CO detectors should not be a substitute for proper use and maintenance of your fuel-burning appliances.  While many authorities recommend their use, it should be realized that the sensitivity and reliability of these devices varies greatly.  Be sure that any CO detector that you buy has received UL certification.  Check the batteries every time you check your smoke detector batteries — at least twice a year.  If an alarm sounds make sure that it is the CO detector rather than the smoke alarm. If anyone in the home is experiencing symptoms of CO poisoning take them to an Emergency Room right away.  If no one is experiencing symptoms, ventilate the house and turn off all fuel-burning appliances. Have a qualified technician inspect the home for potential sources of CO production.